Approval Drawing - A product drawing sent to the customer to verify design and dimensions. Verifies the sales contract description of what the manufacturer has agreed to furnish.

Astragal - A closure between two leaves of a double swing or double slide door used to close the joint.

Automatic Welding - A welding operation utilizing a machine to make a continuous, unbroken weld.

Auxiliary Loads - All live loads, other than the basic design loads which the building must be designed for such as cranes, material handling systems and impact loads.

AWS - American Welding Society.

Return to top

Bar Joist - Normally used as beams or horizontal structural members suitable for the support of floors or roof decks. Bar joists are fabricated with steel bars and formed shapes welded into open web load carrying members.

Base Angle - A continuous angle secured to the perimeter of the foundation to support wall panels.

Base Plate - A plate attached to the base of a column which rests on a concrete floor, foundation of other support, usually secured by anchor bolts.

Base Trim - A light gauge member secured to the perimeter of the base to close off wall panel configurations.

Bay - The space between frame center lines or primary supporting members in the lengthwise direction of the buildings. In endwalls, it is determined by outside girt of endwall to center line of next frame.

Bearing Plate - A steel plate that is set in the top of a masonry wall on which a beam or purlin rests.

Bending Moment - The tendency of an applied load of series of loads acting perpendicularly to a structural member to cause bending in the member. Also, it is the ability of that member to resist the applied member.

Bill of Materials - A list of components used for fabrication, shipping, receiving and accounting purposes.

Bird Screen - Wire mesh used to prevent birds from entering the building through ventilators and louvers.

Bonded Roof - A roof which carries a written warranty with respect to weathertightness for a specified number of years; usually applicable to built-up roofs.

Brace Cables - Rods or cables used in roof and walls to transfer loads such as wind, seismic and crane thrusts to the foundation. (Also, often used to plumb buildings during construction though not intended to replace erecting cables.

Bracket - A structural support projecting from a wall or column on which to fasten another structural member. Examples are canopy brackets, width extension brackets and crane runway brackets.

Bridge Crane - A load lifting system consisting of a hoist which moves laterally on a beam, girder or bridge which in turn normally moves longitudinally on a runway made of beams and rails. Loads can be moved to any point within a rectangle formed by the bridge span and runway length.

Bridging - Bracing or system of bracing used between joists or other structural members to stiffen them and thereby distribute a load.

Building Code - Regulations established by a recognized agency such as U.B.C. describing design loads, procedures, and construction details for structures. Usually applying to designated geographical areas (city, county, state, etc.). The legal requirements set up by various governing agencies covering the minimum requirements for all types of construction.

Building Purchase Order - A building (or parts) order form outlining materials purchased from the manufacturer by the customer. It also gives mode of shipment, point to be shipped, method of payment, etc.

Built-Up Roofing - A type of roof that is applied to a roof deck in layers of tar paper called felt. These layers are mopped with hot, melted asphaltic material as they are applied.

Built-Up Section - A structural member, usually an "I" shape, made from individual flat plates by welding them together.

By-Pass Girt - A cee or zee shaped member mounted outside the columns to the column usually by a clip.

Return to top

"C" Section - A member formed from coiled steel stock in the shape of a block "C" that may be used either singularly or back to back.

Camber - A permanent curvature designed into structural members to offset anticipated deflection when loads are applied.

Canopy - An overhang or projecting roof structure with the extreme end usually unsupported.

Cantilever - A projecting beam or column that is supported and restrained at one end only. A structural member like a truss, beam or slab, projecting from a fixed end. The projected end is free and clear of any support. (e.g. Flag pole, road signs, overhangs)

Cantilever Beam - A beam with support at one end. The support provides restraint against rotation and horizontal and vertical movement.

Capillary Action - That action which causes movement of liquids when in contact with two adjacent surfaces such as panel sidelaps.

Caulk - To seal and make weather-tight at joints, seams or voids by filling with a waterproofing compound or material.

Chalking - Oxidation of the paint vehicle exposing the titanium dioxide to the surface.

Channel: - Hot Rolled - A member formed while in a semi-molten state at the steel mill to a general "C" shape having standard dimensions and properties specified by AISC or the steel producer.

Clear Span - The distance or clear width between two supports of a beam; generally less than the effective span.

Clevis - A device, usually U-shaped, made of iron or steel with the ends drilled to receive a pin. Used in construction to attach a draft chain to a vehicle or a load to a crane cable.

Concentrated Load - A load applied to a structural element that is considered as being applied at a point rather than being applied uniformly across a span. (e.g. a ceiling mounted heater hung from a beam.

Continuous Beam - A beam which has more than two points of support.

Clip - A plate or angle used to fasten two or more members together.

Closer - A mechanical device attached to a door, allowing it to close at normal speed.

Closure Strip - A resilient strip, such as neoprene, flat on one side and formed to the contour of ribbed sheets on the other, used to close openings created by joining metal sheets and flashing.

Cold Forming - The process of using press brakes or rolling mills to shape steel into desired cross sections at room temperature.

Collateral Load - All specified additional dead loads other than the metal building framing such as sprinklers, mechanical and electrical systems, and ceilings.

Column - A primary member used in a vertical position on a building to transfer loads from main roof beams, trusses or rafters to the foundation.

Covering - The exterior roof and wall sheeting for a metal building system.

Crane - A machine designed to move material by means of a hoist.

Crane Rail - A track supporting and guiding the wheels of a bridge crane or trolley system.

Crane Runway Beam - The member that supports a crane rail and is supported by columns or rafters depending on the type of crane system. On underhung bridge cranes, a runway beam also acts as a crane rail.

Curb - A raised edge on a concrete floor slab. Also refers to a "boxed out" opening in a roof for HVAC equipment.

Curtain Wall - Perimeter wall panels which carry only their own weight and wind load. Also as DRAFT curtain referring to an interior partition suspended from the roof structure to a preset elevation above the floor to reduce wind draft in large, open buildings.

Return to top

Damper - A baffle used to open or close the throats of ventilators.

Dead Load - The weight of all permanent construction such as floor, roof, framing and covering members.

Deflection - The displacement of a structural member or system under load. When compared to a static position, the difference is known as its "yield".

Design Loads - Loads specified in building codes published by Federal, State, County or City agencies, or in owner's specifications to be used in the design of a building.

Downspout - A conduit used to carry water from the gutter of a building to the ground or stone drain.

Downspout Elbow - Cold formed sheet metal matching to downspout shape and curved to direct water away from a wall when attached to the lower end of a downspout.

Drift Pin - A tapered pin used during erection to align holes in steel members for connection by bolting.

Return to top

Eave - A line along the roof/sidewall intersection formed by the inside faces of the roof and wall panels.

Eave Height - The vertical dimension from finished floor to the eave.

Eave Strut - A structural member at the eave to support roof panels. It may also transmit wind forces from roof bracing to wall bracing.

Elastic Design - A design concept utilizing the proportional behavior of materials when all stresses are limited to specified allowable values.

Elastic Limit - The furthest point to which an elastic body can be stretched and still return to its original size and shape.

End Frame - A frame at the endwall of a building to support the roof load from one half the end bay.

End Post - A secondary column at the endwall of a building to support the rafters and or girts.

Expansion Joint - A separation between adjoining parts providing small relative movements (occurring independently) such as those caused by temperature changes.

Return to top

Fascia - A decorative trim or panel projecting from the face of a wall.

Filler Strip - See "Closure Strip".

Fire Resistance -A relative term, used with a numerical rating or modifying adjective to indicate the extent to which a material or structure resists the effect of fire. (e.g. Fire resistance of two hours as measured on the standard Time-Temperature curve.

Fixed Base - A column base that is designed to resist rotation as well as horizontal movement.

Flange - The projecting edge of a structural member.

Flange Brace - A bracing member used to provide lateral support to the flange of a beam, rafter or girder. Also called a "Flange Stay".

Flashing - A sheet metal closure which functions primarily to provide weathertightness in a structure and secondarily to enhance appearance.

Force - The action of one body on another which changes or tends to change its state of rest or motion. A force may be expressed in pounds, kips or other similar units and may act in any one of the following ways: A.) Compression B.) Shear C.) Tension D.) Torsion

Framed Opening - Framing (headers and jambs) and flashing which surround an opening of a roof or wall in a building. Used for field installed accessories such as overhead door, windows and smoke hatches.

Frost Line - The greatest depth to which ground may be expected to freeze.

Return to top

Gable - The triangular portion of the endwall of a building directly under the sloping roof and above the eave height line.

Gauge - The numerical designation for the thickness of sheet metal. Also refers to the distance between punched or drilled holes.

Girder - A main horizontal or near horizontal structural member that supports vertical loads. It may consist of several pieces.

Girt - A horizontal secondary structural member attached to sidewall or endwall columns to which wall covering is attached and supported horizontally. Usually a Zee shape.

Return to top

Haunch - The deepened portion of a column or rafter, designed to accommodate the higher bending moments at such points. (Usually occurs at connection of column and rafter).

High Strength Bolts - Any bolt made from steel having a tensile strength in excess of 100,000 pounds per square inch. (e.g. ASTM A-325, A-354, A-449 and A-490).

High Strength Steel - Structural steel having a yield point in excess of 36,000 pounds per square inch.

Hinged Base - See "Pin Connection".

Hip Roof - A roof which rises by inclined planes from all four sides of a building. The line where two adjacent sloping sides of a roof meet.

Holes In Plates - Pitch: The distance between holes along longitudinal axis of plate. Gage: The distance between holes along transverse axis of plate. Edge Distance: Distance from center of hole to edge of plate.

Horizontal Thrust - A lateral load in the horizontal plane. Always present at the base of a loaded rigid frame or arch. The tendency of a rigid frame column to "kick outward" at its base.

Hot Rolled Shapes - Steel sections (angles, channels, I-beams, etc.) which are formed while in a semi-molten state at the steel mill to a shape having standard dimensions and properties specified by AISC or the steel producer.

Return to top

I.C.B.O. - International Conference of Building Officials.

Impact Load - The assumed loading from the motion of machinery, elevators, craneways, vehicles and other similar dynamic forces such as the starting and stopping of an overhead crane.

Return to top

Jack Beam - A primary member used to support another beam or truss and eliminate a column support.

Jamb - The vertical structural member on the sides of a door, window or other framed opening.

Jib Crane - A cantilevered beam or horizontal beam with hoist and trolley. This lifting machine may pick up loads in all or part of a circle around the column to which it is attached.

Joist - A lighter beam for supporting the floor or roof.

Return to top

Kip - A unit of measure equal to 1,000 pounds.

Knee - The joint between the column and rafter of a structural frame such as a rigid frame. Also referred to as "haunch".

Knee Brace - A diagonal brace designed to resist horizontal loads usually from wind or moving equipment. This member normally has the lower end connected to the column and the upper end connected to a rafter or eave strut.

Return to top

Lateral - Proceeding from or directed toward the side of something; such as a column.

Live Load - The temporary load applied to a structure in addition to its own weight. (e.g. People on roof, materials stacked on roof, snow, etc. It does not include wind loads, earthquake loads or dead loads.

Loads - Anything that causes an external force to be exerted on a structural member. (e.g. Dead, impact, roof live load, seismic, wind and crane.

Load Bearing Walls - Any wall that bears its own weight as well as other weight from other sources such as building and wind.

Longitudinal - Pertaining to length, running lengthwise. The longitudinal strength of a structural system is its resistance to forces coming from the end in a lengthwise direction. The bracing system provides most of the longitudinal strength of a building.

Louver - An opening provided with slotted fins (fixed or moveable) to allow air flow.

Moment - The tendency of a force to cause rotation about a point or axis.

Moment Connection - A connection between two members which transfers the moment from one side of the connection to the other side and maintains under application of load the same angle between the connected members that exists prior to the loading. Also, a connection that maintains continuity.

Moment of Inertia - A physical property of a structural member which helps define strength and deflection characteristics.

Monorail - A single rail support for a material handling system. Normally a hot-rolled "I" beam. (EG-hoist)

MS Colorfast45® -This is a thermoset paint system with a 45 year warranty composed of polyester resin which has been modified with a silicone resin. The MS Colorfast45® system offers good protection to the elements with special consideration to chalk and fade resistance, durability, and chemical resistance. See Color Guide for available colors.

MS Strongcoat45® -This is a thermoset paint system with a 45 year warranty composed of polyester resin which has been modified with a silicone resin. This system offers good protection to the elements with special consideration to chalk and fade resistance, durability, and chemical resistance. See Color Guide for available colors.

Prestressed - Usually applies to prefabricated concrete. Before concrete is hardened, the reinforcing steel is pulled or put in tension by jacks at the sides or ends of the concrete form. When the concrete hardens, the stretch of the steel is in tension while the concrete is in compression.

Press Brake - A machine used in cold-forming metal sheet or strip into desired shapes.

Primary Framing - The main load carrying members of a structural system, generally the columns and rafters or other main support members.

Primer Paint - The initial coat of paint applied in the shop to the structural framing of a building for protection against the elements during shipping and erection.

PSF - Unit of measure expressed as pounds per square foot (psf).

PSI - Unit of measure expressed as pounds per square inch (psi).

Purlin - A horizontal secondary structural member bolted to the rafters which transfers the roof loads from the roof panels to the rafters or main frames, usually a Z or C shape.

PVDF (Kynar 500®) This paint system with a 45 year warranty combines ceramic pigmentation with polyvinylidene fluoride for a superior, long-lasting performance. The PVDF system is respected for its durability, resistance to chalking and fading, chemical resistance, and color retention. Please note: the PVDF system meets both Kynar 500/Hylar 5000 specifications and contains 70% Kynar 500® or Hylar 5000 resins. Kynar 500® and Hylar 5000 are produced under license from Atofina and Ausimont, respectively. See Color Guide for available colors.

Return to top

Racking Action - The tendency for a building to lean and/or fall in one direction due to wind loads imposed from an opposite side.

Rafter - A primary beam supporting the roof loads.

Rake - The intersection of the plane of the roof and the plane of the endwall.

Rake Angle - Angle fastened to purlin ends at the rake for attachment of endwall sheets.

Rake Beam - See "End Rafter".

Rake Extension - See" Roof Overhang"

Rake Fascia/Trim - A flashing designed to close the opening between the roof and endwall panels.

Shear Strength - The ability of a structural element to withstand loads of forces perpendicular to its principal access. These loads may be withstood by the structure as a whole, but investigation at particular location within the structure is necessary.

Sheet Notch - A groove or block-out formed along the outside edge of the foundation to provide support for the wall panels and serve as a closure along their bottom edge.

Sheeting - See "Covering".

Shim - A piece of steel used to level or square beams and base plates. Shipping List - See "Bill of Material".

Shop Details/Drawings - Details prepared for and used by manufacturing in the fabrication of parts and assemblies.

Sidelap - A term used to describe the lap condition occurring at the side or lengthwise direction of panels or sheeting.

Sidewall - A term used to describe the entire composition of a building side.

Sill - The bottom horizontal framing member of an opening such as a window or door.

Simple Span - A term used in structural analysis to describe a support condition for a beam, girt, purlin, etc., which offers no resistance to rotation at the support.

Single Slope - Refers to sloping roof with one surface. The slope is from one sidewall of a building to the opposite sidewall.

Siphon Break - A small groove to arrest the capillary action of two adjacent surfaces, usually found at a roof panel sidelap.

Skylight - A reinforced plastic panel fitted into an opening in a roof to admit daylight.

Sleeve Nut - A long, slender nut used to join together two brace rods of the same diameter. -

Slide Door - A single or double leaf door which opens horizontally by means of overhead trolleys.

Sliding Clip - A clip used to attach a standing seam roof to the secondary structural members allowing the roof to expand and contract independently of the structural system.

Snow Load - A load imposed on buildings or other structures due to snowfall.

Soffit - The underside covering of any portion of a metal building usually at a roof overhang.

Soil Pressure - The load per unit area a structure exerts through its foundation to the soil.

Spall - A chip or fragment of concrete that has broken from the main mass of concrete.

Span - The distance between the supports of beams, girders or trusses.

Specification - A statement of particulars of a given job, as to size of building, quality and performance of men and materials to be used, and the terms of the contract. Through the M.B.M.A,, the metal building industry has published a "Recommended Guide Specifications For Pre-Engineered Buildings".

Splice Plate - See "Butt Plate".

Spud Wrench - A long tapering steel handle with a wrench on one end; used by ironworkers to line up holes for bolted connections.

Stainless Steel - An alloy of steel which contains a high percentage of chromium. Also contains copper and 10-30 % of nickel and other metals. Provides excellent resistance to corrosion.

Standing Seam Roof - An exposed metal roof system designed with interlocking sidelaps forming a watertight joint without the use of through fasteners.

Steel Line - The extreme outer limits of a building's structural framing system to which the sheeting is attached.

Stiffener - A member used to strengthen plate against lateral or local buckling. Usually a bar welded perpendicular to the longitudinal axis of the member. Large concentrated loads such as crane loads usually require stiffeners at the point of connection.

Stitch Screw - A self-tapping screw used to connect panels together at the side lap.

Structural Line - See "Steel Line".

Structural Steel Members - Load carrying members such as hot-rolled sections, coldformed shapes or built-up shapes.

Strut - A supporting piece; an inside brace resisting pressure along its length.

Width Extension - A single slope structure dependent upon another structure for partial support. Usually high side eave height of wing unit connects to eave of "stand-alone" building.

Wind Bracing - Cables, rods or other structural members used in roof and walls to transfer loads (wind, seismic and crane thrusts) to the foundation.

Wind Column - A vertical member supporting a wall system designed to withstand horizontal wind loads only.

Wind Load - A load representing the pressure exerted on a structure by a given wind velocity. A load caused by the wind blowing from any horizontal direction.

Wing Unit - See "Width Extension".

Work Point - An intersection of planes from which dimensions are located.

Return to top

"X" Bracing - See "Wind Bracing".

Return to top

Yield Point - The amount of stress under which a given material such as a rod of metal, will exhibit permanent deformation. The point at which a stress or strain exceeds the elastic strength of the material.

Return to top

"Z" Section - A member formed from coiled steel stock in the shape of a block "Z".